Editor's note: This is the first in a series looking back at some of the most important, timely or unusual stories covered by China Daily's reporters last year.

Wang Jiaxue can still remember the garbage classification rules she learned during her first overseas studies in Germany eight years ago.

"In Germany, do as the Germans do," she quipped. "We had to separate glass, plastics, paper and food waste from other residual trash at our dorm and dispose of them one by one in different places. Though it felt troublesome at first, I soon enjoyed doing it because it kept our living environment clean and tidy."

The 30-year-old lives in Shanghai, where a trash-sorting campaign has rekindled her memories of life overseas. "We are experiencing the same process here; some people found it inconvenient at first, but now the majority recognize the benefits."

In January last year, Shanghai's legislators passed a municipal regulation on domestic waste management that requires people to sort their trash into four categories or face fines of up to 200 yuan ($29).

The law went into effect in July, and its strict enforcement and huge media exposure have resonated in cities nationwide, leading experts and industry insiders to say it is a milestone in China's recycling revolution and the long march toward a zero waste society.

"Trash sorting is the hottest topic in the recycling and waste management industry right now," said Fu Tao, president of the E20 Environment Platform, during the think tank's annual forum on solid waste in Beijing on Dec 19.

"In the past, there were more words than concrete acts of trash sorting－because it's tough work," he said. "But it has been pushed along the road this year, and will change the whole industry chain of waste management."

China tested trash sorting as early as 2000, when the central government chose eight cities, including Beijing, Shanghai, and Guangzhou, Guangdong province, as pilots to implement garbage-classification programs, but they bore little fruit until this year.

A report by the Shanghai Municipal People's Congress in November showed that 90 percent of the city's 12,000 residential neighborhoods met municipal trash-sorting standards. In 2018, the figure was just 15 percent.

The report said that in October, the collection of recyclables had risen by 4.6 times from the same month in 2018, while the collection of hazardous waste had risen ninefold and the amount of kitchen waste collected had doubled.

"The results are beyond expectations," said Tang Zhiping, vice-mayor of Shanghai. "The implementation of the new law has greatly increased people's knowledge of, and participation in, trash sorting."

Becoming a habit

A survey released on Dec 3 showed that more than 70 percent of citizens of Shanghai dispose of trash in accordance with the four waste categories, and almost 80 percent have got into the habit of sorting their trash and abiding by the regulation.

Shanghai's move is in line with a more ambitious national plan. In 2017, the State Council, China's Cabinet, stated that it planned to establish standards and duplicable models of domestic garbage sorting systems in all 36 municipalities, provincial capitals and cities under separate planning－those with greater freedom regarding economic planning－by the end of next year. The cities' domestic waste recycling rate must be 35 percent or higher.

In April, nine government bodies－including the National Development and Reform Commission, the Ministry of Housing and Urban-Rural Development and the Ministry of Ecology and Environment－issued a work plan for sorting domestic garbage. It added 10 more cities to the 2020 list, saying that all 300-plus cities at prefecture level and above must establish similar systems by 2025.

Many cities have already formulated waste-management laws or renewed existing legislation. In November, an amendment was approved to Beijing's regulations on the management of domestic waste. It will become effective on May 1. Despite adopting slightly different trash categories, the regulation closely resembles the one in Shanghai because of an economic incentive－a 200 yuan fine for violators.

However, regulations alone won't do any good. Hangzhou, capital of Zhejiang province, introduced a new regulation on domestic waste in August, but has failed to achieve significant progress in terms of participation.

"It's not that you promulgate a new law and people will abide by it," said Yu Wei, vice-secretary-general of the Zhejiang Province Environmental Federation, adding that although the trash bins have been changed in his neighborhood, residents still use them to dispose of mixed trash.

In August, Yu's organization joined other social groups to launch a competition for novel ways of promoting trash sorting. The move attracted 111 proposals, such as a trash-sorting song, a trash-identification program based on artificial intelligence, and collection of expired drugs.

"We are reaching out to people and engaging them in various ways. I think this is the best time to launch trash-sorting initiatives, because there's strong government support," Yu said, adding that more fundamental work will be needed before the rules will translate into daily action.

Zhou Chun, founder of the NGO Trash to Treasure in Shanghai, echoed Yu's words. In 2018, she started implementing trash-sorting programs in Shanghai's residential neighborhoods, and has witnessed the incremental changes in people's behavior. At first, residents were reluctant, so volunteers had to go door to door to explain the program, then stand by garbage stations and correct wrongdoers.

"Now, after thoroughly communicating with residents and property management staff, the 80 neighborhoods in our program don't need supervision anymore," she said.

Business opportunities

The recent development of trash-sorting initiatives has brought business opportunities for Zhou, who has started another project in Zhejiang.

However, she acknowledged that it is harder to push forward trash sorting in other places, because they don't have the same level of governance as Shanghai.

In addition to public advocacy and education, domestic waste management requires separate transportation systems and the construction of dedicated treatment facilities.

A report by Orient Securities, an investment bank and brokerage, estimated that Shanghai's waste-management project has cost 7.6 billion yuan so far. It predicted that the Shanghai model would be extended to every city in the country, producing a market worth about 200 billion yuan.

Wen Zongguo, director of Tsinghua University's Centre for Industry and Circular Economy, said the aim of the national campaign is to reduce the generation of trash to prevent megacities becoming "besieged by waste".

"The nation's move toward recycling and the circular economy through waste management started because China faces a developmental bottleneck－limited natural resources, limited land resources and serious pollution."

In January last year, the State Council issued a plan to build several "waste free" cities, and in May, 11 cities and five areas, including Chongqing, Sanya, Hainan province, and Shenzhen in Guangdong, were selected to pilot waste-free programs led by the Ministry of Ecology and Environment and 17 other ministry-level agencies.

"There are many opportunities and investments in the areas of recycling, waste treatment, renewable resources and the circular economy in the pilot cities," Wen said.

Alizee Buysschaert, a Belgian expat who co-founded the Zero Waste Shanghai project which provides training and workshops on sustainability, said she has been contacted by a growing number of companies in recent months.

"Many are thinking ahead; they asked me that in addition to recycling and waste sorting, what more can they do," she said.

She added that she was recently invited to provide a workshop for employees of a company in Guangzhou, Guangdong's capital.

"Everyone is looking at China right now in terms of recycling and sustainability."

Buysschaert has been interviewed by many foreign media outlets since July. "They want to know what's going on here in China… and you cannot deny that China is the No 1 sustainability leader in the world, and it will remain like this for a very long time," she said.

"We're working toward a greener future every day."